A116949 Riordan array ((1-x^3)/(1+2x^2),x).

1, 0, 1, -2, 0, 1, -1, -2, 0, 1, 4, -1, -2, 0, 1, 2, 4, -1, -2, 0, 1, -8, 2, 4, -1, -2, 0, 1, -4, -8, 2, 4, -1, -2, 0, 1, 16, -4, -8, 2, 4, -1, -2, 0, 1, 8, 16, -4, -8, 2, 4, -1, -2, 0, 1, -32, 8, 16, -4, -8, 2, 4, -1, -2, 0, 1, -16, -32, 8, 16, -4, -8, 2, 4, -1, -2, 0, 1, 64, -16, -32, 8, 16, -4, -8, 2, 4, -1, -2, 0, 1

Offset: 0

Author

Paul Barry, Mar 29 2006

Keywords

• easy
• sign
• tabl

Comments

Sequence array of (-2)^(n/2)(1+(-1)^n)/2-(-2)^((n-3)/2)(1-(-1)^n)/2-(comb(1,n)-comb(0,n))/2.

Inverse of A116948.

Row sums are A117575. Diagonal sums are A117576.

Examples

			Number triangle begins
1,
0, 1,
-2, 0, 1,
-1, -2, 0, 1,
4, -1, -2, 0, 1,
2, 4, -1, -2, 0, 1,
-8, 2, 4, -1, -2, 0, 1,
-4, -8, 2, 4, -1, -2, 0, 1,
16, -4, -8, 2, 4, -1, -2, 0, 1
		

Crossrefs

Cf. A117575, A117576, A116948.

Extensions

Entry revised by N. J. A. Sloane, Apr 10 2006